Coupling for multi-walled lines

Abstract

A coupling for connecting a first and a second multi-walled line ( 203,204 ) having at least two concentric pipes ( 206,207 ) has a female coupling part ( 202 ) with at least two concentric tubes including an inner and an outer tube ( 217,218 ) each connected at one end with one of the concentric pipes ( 206,207 ) of the first multi-walled line ( 204 ), respectively. The coupling further has a male coupling ( 201 ) part having at least two concentric tubes including an inner and an outer tube ( 210,211 ) each connected at one end with one of the concentric pipes ( 206,207 ) of the second multi-walled line ( 203 ). The at least two concentric tubes of the female and/or male coupling parts are compressible and/or expandable in an axial direction to ensure a fluid tight connection between the male and female coupling part is already achieved when the coupling has not yet reached its operation temperature.

The invention claimed is: 
     
         1 . A coupling for connecting a first and a second multi-walled line each one having at least two concentric pipes, which are separated by a space, said coupling comprising:
 a female coupling part comprising at least two concentric tubes including an inner and an outer tube each connected at one end with one of the concentric pipes of the first multi-walled line, wherein the other ends of the at least two concentric tubes are joined in a fluid tight manner, wherein the inner tube is provided with a sealing surface;   a male coupling part comprising at least two concentric tubes including an inner and an outer tube each connected at one end with one of the concentric pipes of the second multi-walled line, wherein the other ends of the at least two concentric tubes are joined in a fluid tight manner,   wherein the at least two concentric tubes of the female and/or male coupling parts are compressible and/or expandable in an axial direction, and   wherein the sealing surface of the female coupling part is provided with a collar.   
     
     
         2 . The coupling according to  claim 1 , wherein the at least two concentric tubes of the female and/or male coupling part are corrugated. 
     
     
         3 . The coupling according to  claim 1 , wherein the sealing surface is angled relative to the axial direction of the inner tube. 
     
     
         4 . The coupling according to  claim 1 , wherein the female and male coupling parts comprise a flange. 
     
     
         5 . The coupling according to  claim 4 , wherein a seal is arranged between the flanges. 
     
     
         6 . The coupling according to  claim 4 , wherein a distance between the front end of the male coupling part and a contact surface of the associated flange is larger than the distance between the surface of the sealing surface of the female coupling part and a contact surface of the associated flange. 
     
     
         7 . The coupling according to  claim 1 , wherein the collar accommodates a tubular and/or conical seal on an inner or outer perimeter of said collar. 
     
     
         8 . The coupling according to  claim 7 , wherein the tubular seal has a larger or smaller coefficient of thermal expansion than the collar. 
     
     
         9 . The coupling according to  claim 1 , wherein the space between the at least two concentric pipes of the first and/or second multi-walled line is evacuated, filled with air, inert gas or with a medium for temperature control of the inner pipe. 
     
     
         10 . A transfer device for cryogenic fluids comprising a coupling according  claim 1 . 
     
     
         11 . A coupling for connecting a first and a second multi-walled line each one having at least two concentric pipes, which are separated by a space, said coupling comprising:
 a female coupling part comprising at least two concentric tubes including an inner and an outer tube each connected at one end with one of the concentric pipes of the first multi-walled line, wherein the other ends of the at least two concentric tubes are joined in a fluid tight manner, wherein the inner tube is provided with a sealing surface; and   a male coupling part comprising at least two concentric tubes including an inner and an outer tube each connected at one end with one of the concentric pipes of the second multi-walled line, wherein the other ends of the at least two concentric tubes are joined in a fluid tight manner,   wherein the at least two concentric tubes of the female and/or male coupling parts are compressible and/or expandable in an axial direction,   wherein the coupling comprises a seal that is arranged between the sealing surface of the female coupling part and a front end of the male coupling part, and   wherein the sealing surface of the female coupling part is provided with a collar.   
     
     
         12 . The coupling according to  claim 11 , wherein the seal is attached to the female or male coupling part.